Here's a fun little focal point for an otherwise plain scarf. Divide your stitches into three and knit each third separately for a while. Braid them. On the following row, Knit across all the stitches again to once again form a solid piece of fabric.
It was amazingly easy. If you use a grippy yarn like mohair or wool, you don't even need to place your stitches on holders. Just go for it! They'll stay put all on their own!